Build fixes

Author: Mikael Wills

.github/workflows/dart.yml

@@ -22,7 +22,7 @@ jobs:
           java-version: '12.x'
       - uses: subosito/flutter-action@v1
         with:
-          channel: 'stable'
+          flutter-version: '3.27.1'
       - name: Install project dependencies
         run: flutter pub get
       - name: Dart Format Check

.github/workflows/pushMaster.yaml

@@ -14,13 +14,13 @@ jobs:
       - name: Install Flutter
         uses: subosito/flutter-action@v2
         with:
-          channel: "stable"
+          flutter-version: "3.27.1"
       - name: Install project dependencies
         run: flutter pub get
       - name: Dart Format Check
         run: dart format lib/ test/ --set-exit-if-changed
       - name: Import Sorter Check
-        run: dart run import_sorter:main
+        run: dart run import_sorter:main --exit-if-changed
       - name: Dart Analyze Check
         run: flutter analyze
       - name: Dart Test Check

lib/src/ua.dart

@@ -319,7 +319,7 @@ class UA extends EventManager {
     int num_sessions = _sessions.length;
 
     // Run  _terminate_ on every Session.
-    _sessions.keys.toList().forEach((String? key, _) {
+    _sessions.keys.toList().forEach((String? key) {
       if (_sessions.containsKey(key)) {
         logger.d('closing session $key');
         try {